Amantadine hydrochloride. Analysis of data related to its proposed use for prevention of A2 influenza virus disease in human beings

Abstract

Tissue culture studies showed that amantadine hydrochloride had a minimal effect on all type A influenza viruses as well as on influenza C, the Sendai strain of parainfluenza virus, rubella virus, and pseudorabies virus. Titration tests with different A2 influenza strains showed that the drug could prevent the spread of infection from cell to cell only when small doses were used for infection in the case of some strains and with much larger doses of other strains. The drug acts by preventing entry of adsorbed virus into the cell. The tests in eggs and mice, even with massive doses of drug, showed significant though minimal effects only when the smallest doses of virus were used for infection. In a single study in ferrets the drug not only failed to protect but markedly aggravated the experimental influenzal infection. The studies on small numbers of human volunteers experimentally infected with 2 different disease producing strains of influenza A2 virus showed a reduction in the number of illnesses with one strain but not with the other. No evidence of significant organ toxicity has been observed thus far.